I have posted on this topic in the past but here are my notes:
Purchased Encore 50 x 209 to replace an older Knight BK-92
New Encore accuracy was out right horrible, it did not matter what combination of bullet, sabot used. The powder was granular Triple 7 both FFg & FFFg. Various primers, load combinations made no improvement. Off the bench I could not hit the same spot twice even at 50 yards.
The scope was a Simmons 44m 3.5 x 10 - TC base with Millet rings. I blamed the scope and sent it in for repair (not holding zero). It was replaced by Simmons with no questions asked within two weeks. I reset the scope and repeated the above, the results were the same. I consulted TC they sent me a free box of 250 grain 45 cal sabot – shock-waves. Same drill – same results. I read about some issues with the QLA at the end of the barrel, I contact the writer that ran the story and he said it’s common that The QLA throws the accuracy way off. Taking matters into my own hands I sent this barrel to SSK Industries had them removed the QLA and recrown the barrel (knowing this would void any warranty) but didn’t care. Upon receipt of the barrel, I again repeated the above steps with the accuracy still horrible. I read about the T-7 crud ring, this primer or that primer ect.. Nothing was making a difference.
I saw an advertisement about BK-209 that was designed for muzzleloaders.. I gave it a try with MMP green sabots (44cal) a 240 grain XTP and CCI-209M primer. I started off with 90 grains, for the 1st time ever this barrel finally was able to hit the same spot. About a month later the screw that holds the forearm standoff to the barrel striped out. This barrel was done.. I found a new barrel on a Christmas sale and bought it.
After setting up the scope I went with BK-209 and various sabot loads. I contact Accurate Arms the makers of BK-209 and they recommend a magnum 209 primer for this powder, so I stuck with my CCI-209M. Finally I had what I wanted this rifle to shoot like it should. My pet load is 110 grains of BK-209 with a CCI-209M primer. MMP Black HPH 12 sabot & Barnes 275 grain .451 caliber spritzer. This runs 1922 feet per second and printed .928” group off the bench at 100 yards. I believe 95% of the problems were due to Triple 7 the other 5% a bad barrel. I will never use T-7 again; BK-209 is my powder of choice for modern muzzloading.
Shortly after all of my issues, I watched an episode of Realtree with David Blanton on the Outdoor Channel. Dave was up in Canada on a muzzleloader hunt for deer. He goes out to sight in his “Encore 50 x 209”. In this episode he shoots and shoots and shoots, he has to move up to 50 yards just to hit paper, and shoots even more. By this time the show is ½ over he is red faced due to the cold weather and likely very upset with all of this trouble. What was he using all of this time… Triple 7!!!
Good luck
B….